Numerous types of foods, including beverages, are packed in cans or glass or PET bottles and are heated or need to be pasteurized. The result is a container of food that needs to be heated to pasteurization temperatures.
Generally, it is highly desirable to heat the containers of food to pasteurization temperatures quickly. First, some foods may degrade if they are exposed to high temperatures for too long due to overcooking or chemical reactions, sometimes with the container.
Prior art container pasteurizing methods have not been designed to pasteurize bottles efficiently and quickly. They often contain multiple heating zones, where each zone uses heat transfer fluids heated to different temperatures. In some cases, a heat transfer fluid is sprayed in one zone, collected, and sprayed in a second zone so that the flow of containers relative to the flow of heat transfer fluid approximates countercurrent flow. Although countercurrent flow is very efficient in liquid-liquid heat exchangers, countercurrent flow is very inefficient for this application. Countercurrent flow requires multiple pumps, controls, and more complicated piping to be implemented for the purpose of pasteurizing containers. Hence, there remains a need to pasteurize containers more efficiently and with less equipment.